The invention relates to a fastening of a riding ring on the casing of a rotary cylinder, in particular a rotary furnace for the heat treatment of free-flowing materials, in particular bulk solids such as raw cement mix, whereby the riding ring, which encircles the rotary casing with clearance, is locked in the axial direction and in the circumferential direction relative to the rotary cylinder via support elements affixed to the casing of the rotary cylinder.
There are mainly two different fastening types used to fasten riding rings to the casing of a rotary cylinder e.g. of a rotary furnace:
1. The so-called loose riding ring fastening (floating tire), known e.g. from DE-A-32 03 241. The riding ring is thereby not rigidly connected with the casing of the rotary cylinder but rather encircles the casing with radial play. On the riding ring station, the radial loads or forces from the furnace cylinder must be fed to the track rollers via the riding ring and to the baseplate via the bearing blocks. The riding ring is smooth on all sides and its axial movement is restricted by the retaining element fastened to the casing of the rotary cylinder. In the circumferential direction, the riding ring can move freely relative to the casing of the furnace and namely on washer plates, which are loosely inserted into the ring gap between the riding ring and the casing of the furnace, whereby any necessary corrections to the play of the riding ring can be made by switching out the washer plates. Ovalizations and other deformations of the casing of the rotary cylinder can be compensated for to a certain extent with this type of riding ring. However, the play of the riding ring and the relative movement of the riding ring must be constantly monitored using a measuring device for the safe and secure operation of this type of riding ring station.
2. The so-called fixed riding ring fastening (fixed tire), known e.g. from DE-A-38 01 231 as well as EP-B-0 765 459. The interior surface of the riding ring fastening known from the first document is provided with cogs like an inner toothed rim, and the riding ring is supported in the axial direction as well as in the circumferential direction on retaining elements welded to the casing of the rotary cylinder via these cogs as well as wedges and washer plates. The riding ring fastening known from the second document has through holes distributed around the perimeter, through which through bolts can be fed, the ends of which are affixed to retaining elements of the casing of the rotary cylinder so that, in this manner, the riding ring is fixed not only in the axial direction but also in the circumferential direction. It is understood that both the planing and shaping of the internal teeth of a riding ring as well as the boring of holes in the riding ring are very costly production steps. Add to this the fact that material sectional weakenings are caused by both the inner teeth as well as by the through holes of the known riding rings, which is why these known riding rings must be constructed to be relatively thick-walled, which in turn leads to higher costs.